Everyone knows William Peter Blatty as the author of The Exorcist, but before that in the 1960s he wrote a comedy novel called Twinkle, Twinkle, ‘Killer’ Kane! It was the feature script of Kane which actually brought Blatty and William Friedkin together, but they couldn’t generate any studio interest – and instead Friedkin famously ended up bringing the author’s other novel to the big screen. It would become one of the most successful and controversial horror films of all time. Years later, Blatty revisited the story of Kane and made it much more of a theological thriller – in fact many see it as the middle novel of a trilogy bookended by Exorcist and Legion – then went on to direct what is now the cult classic adaptation of the novel, called The Ninth Configuration.

The film begins in a military insane asylum located at a castle Dracula would have been proud of – in fact there are posters from that film on the walls. Counted amongst the odd assortment of patients – which include Reno (Exorcist’s Jason Miller) who is trying to put on a version of Hamlet with dogs, Nammack (Shaft’s Moses Gunn) who thinks he’s Superman, and Bennish (Scarface’s Robert Loggia) who is not averse to doing Al Johnson numbers – is an astronaut called Cutshaw who suddenly and inexplicably refused to board a rocket to the moon (Scott Wilson, who would much later play Hershel in The Walking Dead).

Entering the fray is psychiatrist Colonel Kane (a stunning turn from Stacy Keach), here to help Colonel Fell (Ed Flanders from Exorcist III) restore some kind of order. That’s easier said that done when everyone, including the staff, seems to be as nutty as a fruitcake. Kane winds up having an ongoing discussion with Cutshaw about whether there’s a God – or as Cutshaw calls Him, ‘a foot’. The astronaut believes in the Devil because of all the bad in the world, so Kane asks him why he doesn’t believe in the Almighty because of all the good? But Kane himself is hiding a dark past, and it all culminates in a bar brawl with a gang of bikers that might just end up proving both their points.

It’s hard to describe what kind of movie The Ninth Configuration is. Part M.A.S.H., part One Flew Over the Cuckoo’s Nest, part Shutter Island and part Rambo, even first time director Blatty admits himself it’s difficult to pigeonhole. Which, of course, accounts for much of its charm – in addition to its cult status (the film didn’t fare well commercially at the time of release in 1980). It can make you laugh – the first two thirds being pure madcap farce, that captures the feel of a mental institution perfectly – it can make you cry and, just like all of Blatty’s work, it will definitely make you think; there are debates in this that I don’t think you’d get away with presenting in any other kind of film.

But, as Blatty says himself in the extras interview – and paraphrasing Woody Allen – directing is 70% good casting, and with these guys you couldn’t really go far wrong. Each performance is right on the money, and I defy anyone not to be mesmerised by both Keach’s and Wilson’s especially. You have to wonder what would have happened had the first choice of Chuck Heston for Kane actually come about…

Speaking of the extras, there is much to cherish here, from the audio commentary and a brand new interview with Blatty already mentioned, to chats with Keach, composer Barry De Vorzon and production designer William Malley – not to mention archive interviews with Tom Atkins (who played Sgt. Krebs), Miller and Richard Lynch (who was a member of the biker gang) plus a Mark Kermode introduction. It’s worth it just to hear the story of the real bar fight involving Miller and a Nigerian ambassador! In short, a highly recommended release.